Without Intellisense, I'm Nothing

Imagine you're given a task: write the code for a program in a hitherto unknown DSL, embedding that code within a hitherto unknown markup language. What would be your tool of choice? Without any easily understood reference documentation, it's not going to be easy. Without the visual clues that you're missing a quote (or your string contains an extra quote) or that your function call doesn't exist or has the wrong arguments, you're going to have to run the program just to debug it. If that running process involved multiple clicks and typing followed by a short wait, you're going to get frustrated and probably won't deliver the program on time. Intellisense is great. You can write Javascript inside an HTML page, and Visual Studio will squiggle under everything you've done wrong!